LXR linux/arch/arm/lib/io-readsb.S

   1/*
   2 *  linux/arch/arm/lib/io-readsb.S
   3 *
   4 *  Copyright (C) 1995-2000 Russell King
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License version 2 as
   8 * published by the Free Software Foundation.
   9 */
  10#include <linux/linkage.h>
  11#include <asm/assembler.h>
  12
  13.Linsb_align:   rsb     ip, ip, #4
  14                cmp     ip, r2
  15                movgt   ip, r2
  16                cmp     ip, #2
  17                ldrb    r3, [r0]
  18                strb    r3, [r1], #1
  19                ldrgeb  r3, [r0]
  20                strgeb  r3, [r1], #1
  21                ldrgtb  r3, [r0]
  22                strgtb  r3, [r1], #1
  23                subs    r2, r2, ip
  24                bne     .Linsb_aligned
  25
  26ENTRY(__raw_readsb)
  27                teq     r2, #0          @ do we have to check for the zero len?
  28                moveq   pc, lr
  29                ands    ip, r1, #3
  30                bne     .Linsb_align
  31
  32.Linsb_aligned: stmfd   sp!, {r4 - r6, lr}
  33
  34                subs    r2, r2, #16
  35                bmi     .Linsb_no_16
  36
  37.Linsb_16_lp:   ldrb    r3, [r0]
  38                ldrb    r4, [r0]
  39                ldrb    r5, [r0]
  40                mov     r3, r3,     put_byte_0
  41                ldrb    r6, [r0]
  42                orr     r3, r3, r4, put_byte_1
  43                ldrb    r4, [r0]
  44                orr     r3, r3, r5, put_byte_2
  45                ldrb    r5, [r0]
  46                orr     r3, r3, r6, put_byte_3
  47                ldrb    r6, [r0]
  48                mov     r4, r4,     put_byte_0
  49                ldrb    ip, [r0]
  50                orr     r4, r4, r5, put_byte_1
  51                ldrb    r5, [r0]
  52                orr     r4, r4, r6, put_byte_2
  53                ldrb    r6, [r0]
  54                orr     r4, r4, ip, put_byte_3
  55                ldrb    ip, [r0]
  56                mov     r5, r5,     put_byte_0
  57                ldrb    lr, [r0]
  58                orr     r5, r5, r6, put_byte_1
  59                ldrb    r6, [r0]
  60                orr     r5, r5, ip, put_byte_2
  61                ldrb    ip, [r0]
  62                orr     r5, r5, lr, put_byte_3
  63                ldrb    lr, [r0]
  64                mov     r6, r6,     put_byte_0
  65                orr     r6, r6, ip, put_byte_1
  66                ldrb    ip, [r0]
  67                orr     r6, r6, lr, put_byte_2
  68                orr     r6, r6, ip, put_byte_3
  69                stmia   r1!, {r3 - r6}
  70
  71                subs    r2, r2, #16
  72                bpl     .Linsb_16_lp
  73
  74                tst     r2, #15
  75                ldmeqfd sp!, {r4 - r6, pc}
  76
  77.Linsb_no_16:   tst     r2, #8
  78                beq     .Linsb_no_8
  79
  80                ldrb    r3, [r0]
  81                ldrb    r4, [r0]
  82                ldrb    r5, [r0]
  83                mov     r3, r3,     put_byte_0
  84                ldrb    r6, [r0]
  85                orr     r3, r3, r4, put_byte_1
  86                ldrb    r4, [r0]
  87                orr     r3, r3, r5, put_byte_2
  88                ldrb    r5, [r0]
  89                orr     r3, r3, r6, put_byte_3
  90                ldrb    r6, [r0]
  91                mov     r4, r4,     put_byte_0
  92                ldrb    ip, [r0]
  93                orr     r4, r4, r5, put_byte_1
  94                orr     r4, r4, r6, put_byte_2
  95                orr     r4, r4, ip, put_byte_3
  96                stmia   r1!, {r3, r4}
  97
  98.Linsb_no_8:    tst     r2, #4
  99                beq     .Linsb_no_4
 100
 101                ldrb    r3, [r0]
 102                ldrb    r4, [r0]
 103                ldrb    r5, [r0]
 104                ldrb    r6, [r0]
 105                mov     r3, r3,     put_byte_0
 106                orr     r3, r3, r4, put_byte_1
 107                orr     r3, r3, r5, put_byte_2
 108                orr     r3, r3, r6, put_byte_3
 109                str     r3, [r1], #4
 110
 111.Linsb_no_4:    ands    r2, r2, #3
 112                ldmeqfd sp!, {r4 - r6, pc}
 113
 114                cmp     r2, #2
 115                ldrb    r3, [r0]
 116                strb    r3, [r1], #1
 117                ldrgeb  r3, [r0]
 118                strgeb  r3, [r1], #1
 119                ldrgtb  r3, [r0]
 120                strgtb  r3, [r1]
 121
 122                ldmfd   sp!, {r4 - r6, pc}
 123ENDPROC(__raw_readsb)
 124